210Polonium is a radioactive daughter of radon. It is an alpha emitter and thus hazardous if allowed to enter the body. For man, inhalation and ingestion are the major portals of entry. There have been "disasters" caused by accidents with 210Po, e.g. the Windscale accident in England. One of the occupational dangers of uranium miners is 210Po inhalation. There has been recent concern about radon and 210Po concentrations in the interior air of poorly ventilated buildings and homes resulting from materials used in site preparation and/or construction materials. In addition, accidents in nuclear facilities have occurred with 210Po. The results of a small preliminary experiment in this laboratory indicate that the administration of either DMSA or DMPA, water soluble and less toxic analogs of BAL, protects rats from a subacute lethal dose of 210Po. Our aims are to confirm and expand the results of the initial preliminary experiment, to determine whether BAL analogs redistribute 210Po from radiation sensitive tissue (e.g. spleen) to radiation insensitive tissues (e.g. muscle), to determine if these dithiols increase 210Po excretion and to determine whether BAL and its less toxic analogs differ in life-saving activity in rats given a lethal dose of 210Polonium. These studies can help evaluate the damage done to a living body by the presence of alpha emitters in mining environments, in some poorly ventilated work places and houses, in nuclear facilities and other environments. In addition, it can make experimental information available to physicians who have to treat humans after exposure to alpha emitters.